309397 has 6 divisors (see below), whose sum is σ = 340214. Its totient is φ = 281160.

The previous prime is 309391. The next prime is 309403. The reversal of 309397 is 793903.

It is an interprime number because it is at equal distance from previous prime (309391) and next prime (309403).

It can be written as a sum of positive squares in only one way, i.e., 256036 + 53361 = 506^2 + 231^2 .

It is not a de Polignac number, because 309397 - 2⁷ = 309269 is a prime.

It is a Duffinian number.

309397 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309391) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1158 + ... + 1399.

2³⁰⁹³⁹⁷ is an apocalyptic number.

It is an amenable number.

309397 is a deficient number, since it is larger than the sum of its proper divisors (30817).

309397 is a wasteful number, since it uses less digits than its factorization.

309397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2579 (or 2568 counting only the distinct ones).

The product of its (nonzero) digits is 5103, while the sum is 31.

The square root of 309397 is about 556.2346627099. The cubic root of 309397 is about 67.6350838509.

The spelling of 309397 in words is "three hundred nine thousand, three hundred ninety-seven".